Up to 1.4 million call logs of Softbank Corp. group’s BB Phone Internet protocol telephone service might have been stolen in January by a group of extortionists, police sources said Friday.
Yutaka Tomiyasu, 24, who was arrested in May on suspicion of attempting to extort money from Softbank over leaked Internet user data, has confessed to stealing the IP user call logs and users’ personal information, including names and addresses, the sources said.
BB Phone is the largest provider in Japan of low-cost IP telephone services.
The Metropolitan Police Department discovered the theft when it seized papers with dozens of BB Phone call logs from the home in Ibaraki Prefecture of relatives of Hiroshi Mori, 67, a former rightwing group leader, who is also charged with attempted extortion over the leaked Internet user data, they said.
The logs show the users’ telephone numbers, the numbers they had called, the times the calls were made, the length of each call and the individual charges.
There were no names of the users or call receivers on the seized documents, the sources said.
In a statement, Softbank BB Corp. said it received inquiries from the MPD for about 65 call logs of 23 people, and it confirmed that the logs were those of the BB Phone service.
The company said it is currently speaking to the MPD to verify media reports that as many as 1.4 million call logs may have been stolen.
The police sources said Tomiyasu has admitted keeping the call logs on his computer after he stole it in January along with the personal information, but said he later deleted the logs and did not use them in the extortion attempt.
Investigators suspect Tomiyasu obtained a password for the Softbank BB database from a hacker friend who had worked for the firm on a contract basis, and broke into the database from a computer at an Internet cafe, the sources said.
Tomiyasu, Mori and several others are suspected of attempting to extort billions of yen from Softbank by threatening to publish the personal information of some 4.6 million subscribers to the Internet and phone service.